At present, orally administered drugs are available in the market as solid preparations such as uncoated tablets, coated tablets, capsules, powders, and granules; liquid preparations such as liquids and emulsions; and the like. Moreover, orally disintegrating tablets and rapidly dissolving oral film-form preparations are already on the market as preparations that disintegrate in the mouth and are absorbed by the gastrointestinal tracts.
Orally administrated film-, tape-, or sheet-form preparations that are to be disintegrated or dissolved by saliva without being chewed are already available as ethical pharmaceuticals or over-the-counter drugs (OTC drugs) overseas and in Japan.
For example, the following technologies relating to such film-form preparations are disclosed. Abase for a preparation which is obtained by dissolving, in a solvent, hydroxypropyl cellulose or a mixture of hydroxypropyl cellulose with polyvinylpyrrolidone, and a tannin substance, and then removing the solvent (see, Patent literature 1). A film-form troche which is obtained by laminating a coating layer (a) containing a water-soluble, non-hygroscopic polysaccharide and a softener, a drug layer (b) containing a drug and an edible water-soluble polymer, and a drug layer (c) containing a drug, an edible water-soluble polymer, and a tannin substance in the order of (a), (b), (c), (b), and (a) (see, Patent Literature 2). A rapidly dissolving film-form preparation which contains a drug and an edible polymer substance, has a film breaking strength of 200 to 3000 g/ϕ 7 mm and a film tensile strength of 200 to 3000 g/15 mm, and melts within 60 seconds in the mouth (see, Patent Literature 3). An oral film preparation that contains one of a pregelatinized starch and pullulan; an enzyme-modified starch; and a plasticizer (see, Patent Literature 4). A soluble film-form preparation which contains an active ingredient having a water solubility of about less than 1 g/4 mL at room temperature, and has a moisture content of about less than 15 wt % (see, Patent Literature 5). A film-form preparation which contains a drug, an edible water-soluble film forming agent, and low-substituted hydroxypropyl cellulose with a molar substitution degree of 0.05 to 1.0 (see, Patent Literature 6). A technology of preparing a rapidly dissolving preparation, which rapidly disintegrate or dissolve in the mouth or the like, by dissolving or dispersing a drug, saccharides, and polyvinylpyrrolidone in an organic solvent, and then removing the organic solvent (see, Patent Literature 7).
However, the film-form bases and preparations having been disclosed up to now are produced by dispersing or dissolving a drug in a water-soluble polymer. For example, Patent Literatures 3 and 4 teach addition of sugars or sugar alcohols in the bases and preparations. The sugars or sugar alcohols to be used are preliminary dissolved in a solvent or recrystallized. For this reason, those conventional oral film-form bases or preparations give a sticky sensation attributed to the water-soluble polymer when applied in the mouth and also when handled with fingers.
In order to solve the above problems, Patent Literatures 8 and 9 teach film-form preparations including fine particles of sugars and sugar alcohols supported in their original particle forms on a film. Moreover, Patent Literatures 10, 11, and the like, for example, teach other technologies to prepare rapidly dissolving preparations using foaming ingredients which foam upon contacting with water for achieving better taking property. However, the preparations have a two-layered structure (Patent Literature 10), or contain, as a foaming ingredient, a foaming agent that may foam in the presence of protonic solvents such as ethanol (Patent Literature 11), and thus have problems in terms of productivity and feasibility.